Outboard motor control device, outboard motor control method, and program

ABSTRACT

This outboard motor control device controls a plurality of outboard motors disposed on a rear portion of a hull of a boat. Each of the outboard motors includes a propulsion unit and a steering actuator. A boat includes an operation unit configured to operate the steering actuator and the propulsion unit. The operation unit is able to be positioned at a first position where the outboard motors do not generate a propulsion force of the boat and a second position where the outboard motors generate a propulsion force for moving the boat in a left-right direction. When the operation unit is moved from the first position to the second position and maintained at the second position, the outboard motors generate a first propulsion force during a first period from a first timing when the operation unit is moved to the second position to a second timing and subsequently generate a second propulsion force greater than the first propulsion force during a second period after the second timing.

CROSS REFERENCE TO RELATED APPLICATIONS

This is the U.S. national stage of application No. PCT/IB2020/051230, filed on Feb. 14, 2020. Priority under 35 U.S.C. § 119(a) and 35 U.S.C. § 365(b) is claimed from Japanese Application No. 2019-007331 filed Jan. 18, 2019, the disclosure of which is also incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an outboard motor control device, an outboard motor control method, and a program.

BACKGROUND ART

Conventionally, a boat control device capable of moving and turning in any direction is known (see, for example, Patent Literature 1). In technology described in Patent Literature 1, two propulsion units capable of arbitrarily setting a direction and strength of a propulsion force are installed on the left and right sides of a stern and the direction and strength of the propulsion force of each propulsion unit are controlled, so that a composite force with which the boat can move in a desired direction and a composite force with which the boat can turn in a desired direction act on a hull. Specifically, in Patent Literature 1, an example in which a joystick is described as an omnidirectional controller and the hull moves just to the side while maintaining its attitude is described. Also, in Patent Literature 1, an example in which the hull moves diagonally forward or diagonally rearward while maintaining its attitude is described.

Incidentally, in Patent Literature 1, when a tip of a lever of the joystick is moved from a neutral position where the lever is not tilted to a right tilt position where the lever is tilted to the right, a relationship between an elapsed time period from a timing when the tip of the lever of the joystick is moved to the right tilt position and a magnitude of a rightward propulsion force (a composite force) generated by the two propulsion units is not described.

Also, conventionally, a control device for controlling two outboard motors attached to a rear portion of a hull of a boat in accordance with an operation by a joystick capable of tilting the boat from a neutral state in all directions is known (see, for example, Patent Literature 2). In technology described in Patent Literature 2, when the joystick is tilted to the right, the control device causes the two outboard motors to generate a propulsion force with which the boat performs parallel movement to the right. Also, in the technology described in Patent Literature 2, when the joystick is tilted to the right-forward side, the control device causes the two outboard motors to generate a propulsion force with which the boat performs parallel movement in a right-forward direction.

Incidentally, in Patent Literature 2, when the tip of the lever of the joystick is moved from a neutral position to a right tilt position, a relationship between an elapsed time period from a timing when the tip of the lever of the joystick is moved to the right tilt position and a magnitude of a rightward propulsion force (a composite force) generated by the two propulsion units is not described.

CITATION LIST Patent Literature [Patent Document 1]

Japanese Unexamined Patent Application, First Publication No. H1-285486

[Patent Document 2]

Japanese Patent No. 5987624

SUMMARY OF INVENTION Technical Problem

A boat operator moves the tip of the lever of the joystick from the neutral position to the right tilt position so that the boat, which is stopped, is moved to the right.

From intensive research, the inventors of the present invention and the like have found that, in a boat in which an outboard motor is disposed on a rear portion of a hull and is not disposed on a front portion of the hull, when a tip of a lever of a joystick is moved from a neutral position to a right tilt position, if the boat generates a large rightward propulsion force, a start of a rightward movement of the front portion of the hull is later than a start of a rightward movement of the rear portion of the hull, so that the boat turns counterclockwise (i.e., the attitude of the hull changes and the front and rear portions of the hull do not perform translational movement to the right).

In view of the above-described problems, an objective of the present invention is to provide an outboard motor control device, an outboard motor control method, and a program capable of restricting a boat from turning due to the start of a movement of a front portion of a hull being later than the start of a movement of a rear portion of the hull when the boat, which is stopped, is moved in a left-right direction.

Solution to Problem

From intensive research, the inventors of the present invention and the like have found that, for example, when a tip of a lever of a joystick is moved from a neutral position to a right tilt position, an outboard motor first generates a small rightward propulsion force and subsequently generates a large rightward propulsion force, so that the boat performs translational movement to the right without the start of a movement of a front portion of a hull being later than the start of a movement of a rear portion of the hull (i.e., the boat does not turn).

According to an aspect of the present invention, there is provided an outboard motor control device for controlling a plurality of outboard motors disposed on a rear portion of a hull of a boat, wherein each of the plurality of outboard motors includes a propulsion unit configured to generate a propulsion force and a steering actuator, wherein the boat includes an operation unit configured to operate the steering actuator and the propulsion unit, wherein the operation unit is able to be positioned at least at a first position that is a position where the plurality of outboard motors do not generate a propulsion force of the boat and a second position that is a position where the plurality of outboard motors generate a propulsion force for moving the boat in a left-right direction, and wherein, when the operation unit is moved from the first position to the second position and maintained at the second position, the outboard motor control device causes the plurality of outboard motors to generate a first propulsion force during a first period from a first timing when the operation unit is moved to the second position to a second timing and subsequently causes the plurality of outboard motors to generate a second propulsion force greater than the first propulsion force during a second period after the second timing.

According to an aspect of the present invention, there is provided an outboard motor control method of controlling a plurality of outboard motors disposed on a rear portion of a hull of a boat, wherein each of the plurality of outboard motors includes a propulsion unit configured to generate a propulsion force and a steering actuator, wherein the boat includes an operation unit configured to operate the steering actuator and the propulsion unit and an outboard motor control device configured to control the plurality of outboard motors, wherein the operation unit is able to be positioned at least at a first position that is a position where the plurality of outboard motors do not generate a propulsion force of the boat and a second position that is a position where the plurality of outboard motors generate a propulsion force for moving the boat in a left-right direction, and wherein the outboard motor control method includes: a first step in which the outboard motor control device causes the plurality of outboard motors to generate a first propulsion force during a first period from a first timing when the operation unit is moved to the second position to a second timing when the operation unit is moved from the first position to the second position and maintained at the second position; and a second step in which the outboard motor control device causes the plurality of outboard motors to generate a second propulsion force greater than the first propulsion force during a second period after the second timing when the operation unit is moved from the first position to the second position and maintained at the second position.

According to an aspect of the present invention, there is provided a program for controlling a plurality of outboard motors disposed on a rear portion of a hull of a boat, wherein each of the plurality of outboard motors comprises a propulsion unit configured to generate a propulsion force and a steering actuator, wherein the boat includes an operation unit configured to operate the steering actuator and the propulsion unit, wherein the operation unit is able to be positioned at least at a first position that is a position where the plurality of outboard motors do not generate a propulsion force of the boat and a second position that is a position where the plurality of outboard motors generate a propulsion force for moving the boat in a left-right direction, and wherein the program causes a computer mounted in the boat to execute: a first step in which the plurality of outboard motors generate a first propulsion force during a first period from a first timing when the operation unit is moved to the second position to a second timing when the operation unit is moved from the first position to the second position and maintained at the second position; and a second step in which the plurality of outboard motors generate a second propulsion force greater than the first propulsion force during a second period after the second timing when the operation unit is moved from the first position to the second position and maintained at the second position.

Advantageous Effects of Invention

According to the present invention, it is possible to provide an outboard motor control device, an outboard motor control method, and a program capable of restricting a boat from turning due to the start of a movement of a front portion of a hull being later than the start of a movement of a rear portion of the hull when the boat, which is stopped, is moved in a left-right direction.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing an example of a boat to which an outboard motor control device of a first embodiment is applied.

FIG. 2 is a functional block diagram of main parts of the boat shown in FIG. 1.

FIG. 3A-FIG. 3I are diagrams for describing an example of positions of an operation unit in the boat of the first embodiment.

FIG. 4A-FIG. 4E are diagrams for describing an example of a movement path of the operation unit in the boat of the first embodiment.

FIG. 5A-FIG. 5E are diagrams for describing an example of a movement path of the operation unit in the boat of the first embodiment.

FIG. 6A-FIG. 6B are diagrams showing a relationship between a timing and a rightward propulsion force generated by steering actuators and propulsion units.

FIG. 7A-FIG. 7D are diagrams showing a comparison of a right-forward propulsion force the outboard motor control device causes outboard motors to generate in an example shown in FIG. 4B, a right-forward propulsion force the outboard motor control device causes the outboard motors to generate in an example shown in FIG. 4C, and the like.

FIG. 8A-FIG. 8B are diagrams showing an example of a relationship between a timing and a rightward propulsion force generated by the steering actuators and the propulsion units (or a left-right direction component of a right-forward propulsion force) in the example shown in FIG. 4C and the like.

FIG. 9A-FIG. 9B are diagrams showing an example of a relationship between a timing and a rightward propulsion force generated by the steering actuators and the propulsion units (or a left-right direction component of a right-rearward propulsion force) in the example shown in FIG. 4E and the like.

FIG. 10A-FIG. 10B are diagrams showing a relationship between a timing and a leftward propulsion force generated by the steering actuators and the propulsion units.

FIG. 11 is a flowchart for describing an example of a process executed by the outboard motor control device of the first embodiment.

FIG. 12 is a diagram showing an example of a boat to which an outboard motor control device of a second embodiment is applied.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, a first embodiment of an outboard motor control device, an outboard motor control method, and a program of the present invention will be described.

FIG. 1 is a diagram showing an example of a boat 1 to which an outboard motor control device 14 of the first embodiment is applied. FIG. 2 is a functional block diagram of main parts of the boat 1 shown in FIG. 1.

In the examples shown in FIG. 1 and FIG. 2, the boat 1 includes a hull 11, an outboard motor 12, an outboard motor 13, and an outboard motor control device 14. The outboard motors 12 and 13 are propulsion units of the boat 1.

Although the boat 1 includes the two outboard motors 12 and 13 in the examples shown in FIG. 1 and FIG. 2, the boat 1 may include three or more outboard motors in another example.

In the examples shown in FIG. 1 and FIG. 2, the outboard motor 12 is attached to a right side part on the rear portion 112 of the hull 11. The outboard motor 12 includes an outboard motor main body 12A and a bracket 12B. The bracket 12B is a mechanism for attaching the outboard motor 12 to the right side part on the rear portion 112 of the hull 11. The outboard motor main body 12A is connected to the right side part on the rear portion 112 of the hull 11 via the bracket 12B so that the outboard motor main body 12A can rotate with respect to the hull 11 around a steering shaft 12AX.

The outboard motor main body 12A includes a propulsion unit 12A1 and a steering actuator 12A2. The propulsion unit 12A1 is, for example, a propeller-specification propulsion unit driven by an engine (not shown) and generates the propulsion force of the boat 1. In another example, the propulsion unit 12A1 may be a water jet propulsion unit.

The steering actuator 12A2 causes the entire outboard motor main body 12A including the propulsion unit 12A1 to rotate with respect to the hull 11 around the steering shaft 12AX. The steering actuator 12A2 serves as a rudder.

In the examples shown in FIG. 1 and FIG. 2, the outboard motor 13 is attached to a left side part on the rear portion 112 of the hull 11. The outboard motor 13 includes an outboard motor main body 13A and a bracket 13B. The bracket 13B is a mechanism for attaching the outboard motor 13 to the left side part on the rear portion 112 of the hull 11. The outboard motor main body 13A is connected to the left side part on the rear portion 112 of the hull 11 via the bracket 13B so that the outboard motor main body 13A can rotate with respect to the hull 11 around the steering shaft 13AX.

The outboard motor main body 13A includes a propulsion unit 13A1 and a steering actuator 13A2. Like the propulsion unit 12A1, the propulsion unit 13A1 is, for example, a propeller-specification propulsion unit, and generates the propulsion force of the boat 1. In another example, the propulsion unit 13A1 may be a water jet propulsion unit.

The steering actuator 13A2 causes the entire outboard motor main body 13A including the propulsion unit 13A1 to rotate with respect to the hull 11 around the steering shaft 13AX. The steering actuator 13A2 serves as a rudder.

In the example shown in FIG. 1 and FIG. 2, the hull 11 includes a steering device 11A, a remote control device 11B, a remote control device 11C, and an operation unit 11D.

In another example, the hull 11 may not include the steering device 11A, the remote control device 11B, and the remote control device 11C.

In the example shown in FIG. 1 and FIG. 2, the steering device 11A is a device that operates the steering actuators 12A2 and 13A2, and is, for example, a steering device having a steering wheel. By operating the steering device 11A, a boat operator can operate the steering actuators 12A2 and 13A2 to steer the boat 1.

The remote control device 11B is a device that receives an input operation for operating the propulsion unit 12A1, and includes, for example, a remote control lever. The boat operator can change a magnitude and a direction of the propulsion force generated by the propulsion unit 12A1 by operating the remote control device 11B. The remote control lever of the remote control device 11B can be positioned in a forward region where the propulsion unit 12A1 generates a forward propulsion force of the boat 1, a rearward region where the propulsion unit 12A1 generates a rearward propulsion force of the boat 1, and a neutral region where the propulsion unit 12A1 generates no propulsion force. The magnitude of the forward propulsion force of the boat 1 generated by the propulsion unit 12A1 changes with the position of the remote control lever within the forward region. Also, the magnitude of the rearward propulsion force of the boat 1 generated by the propulsion unit 12A1 changes with the position of the remote control lever in the rearward region.

In the examples shown in FIG. 1 and FIG. 2, the remote control device 11C is a device that receives an input operation for operating the propulsion unit 13A1, and has a configuration similar to that of the remote control device 11B. That is, the boat operator can change a magnitude and a direction of the propulsion force generated by the propulsion unit 13A1 by operating the remote control device 11C.

The operation unit 11D is a device that operates the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1. Specifically, the operation unit 11D receives input operations for operating the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1. The operation unit 11D is provided separately from the steering device 11A and the remote control devices 11B and 11C.

In the boat 1 of the first embodiment, the operation unit 11D includes a joystick having a lever.

The boat operator can operate the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 by operating the steering device 11A (a steering wheel) and the remote control devices 11B and 11C (remote control levers) and can also operate the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 by operating the operation unit 11D (a joystick).

In the examples shown in FIG. 1 and FIG. 2, the outboard motor control device 14 controls the steering actuator 12A2 and the propulsion unit 12A1 of the outboard motor 12 and the steering actuator 13A2 and the propulsion unit 13A1 of the outboard motor 13 on the basis of the input operation on the operation unit 11D. Specifically, the outboard motor control device 14 controls a magnitude and a direction of the propulsion force of the boat 1 that is generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 on the basis of the input operation on the operation unit 11D.

The outboard motor control device 14 includes a movement path calculation unit 14A, an elapsed time calculation unit 14B, and a propulsion force calculation unit 14C. The movement path calculation unit 14A calculates a movement path of the operation unit 11D. Specifically, the movement path calculation unit 14A calculates a movement path of a tip of the lever of the joystick on the basis of a position of the lever of the joystick detected by a sensor (not shown) such as a microswitch.

The elapsed time calculation unit 14B calculates an elapsed time period from a timing when the operation unit 11D (the tip of the lever of the joystick) is moved to a certain position.

The propulsion force calculation unit 14C calculates a propulsion force to be generated by the outboard motors 12 and 13 on the basis of the movement path of the operation unit 11D calculated by the movement path calculation unit 14A and the elapsed time period calculated by the elapsed time calculation unit 14B. Specifically, the propulsion force calculation unit 14C calculates a magnitude and a direction of the propulsion force of the boat 1 to be generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 on the basis of the movement path of the tip of the lever of the joystick and a time period (an elapsed time period) for which the tip of the lever of the joystick is continuously positioned at a certain position.

That is, the outboard motor control device 14 controls the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 so that the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 generate the propulsion force of the magnitude and the direction calculated by the propulsion force calculation unit 14C.

In the examples shown in FIG. 1 and FIG. 2, the operation unit 11D is configured so that the lever of the operation unit 11D (the joystick) can be tilted and the lever can rotate around a central axis of the lever.

When the boat operator rotates the lever clockwise around the central axis of the lever, the outboard motor control device 14 controls the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 so that the hull 11 turns to the right. On the other hand, when the boat operator rotates the lever counterclockwise around the central axis of the lever, the outboard motor control device 14 controls the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 so that the hull 11 turns to the left. That is, when the boat operator rotates the lever around the central axis of the lever, the direction of the front portion 111 of the hull 11 changes.

Also, when the boat operator tilts the lever, the outboard motor control device 14 controls the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 so that the hull 11 moves while maintaining its attitude. That is, when the boat operator tilts the lever, the front portion 111 of the hull 11 and the rear portion 112 of the hull 11 are translated.

FIG. 3A-FIG. 3I are diagrams for describing an example of positions of the operation unit 11D (specifically, positions P1 to P9 of the tip of the lever of the joystick) in the boat 1 of the first embodiment.

In the example shown in FIG. 3A, the lever of the operation unit 11D (the joystick) is not tilted. Thus, the operation unit 11D (specifically, the tip of the lever of the joystick) is positioned at the position (the neutral position) P1. When the operation unit 11D (the tip of the lever of the joystick) is positioned at the position P1, the outboard motor control device 14 does not cause the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate the propulsion force of the boat 1.

That is, the position P1 is a position where the outboard motors 12 and 13 generates no propulsion force of the boat 1.

In the example shown in FIG. 3B, the lever of the joystick is tilted to the right. Thus, the tip of the lever of the joystick is positioned at the position P2 on the right side of the position P1. When the tip of the lever of the joystick is positioned at the position P2, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a propulsion force for moving the boat 1 to the right.

That is, the position P2 is a position where the outboard motors 12 and 13 generate a propulsion force for moving the boat 1 to the right (specifically, translational movement).

In the example shown in FIG. 3C, the lever of the joystick is tilted in a right-forward direction. Thus, the tip of the lever of the joystick is positioned at the position P3 on the right front side of the position P1. When the tip of the lever of the joystick is positioned at the position P3, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a propulsion force for moving the boat 1 in the right-forward direction forming an acute angle θ3 with respect to the left-right direction.

That is, the position P3 is a position where the outboard motors 12 and 13 generate a propulsion force for moving the boat 1 in the right-forward direction (translational movement).

In the example shown in FIG. 3D, the lever of the joystick is tilted in a right-rearward direction. Thus, the tip of the lever of the joystick is positioned at the position P4 on the right rear side of the position P1. When the tip of the lever of the joystick is positioned at the position P4, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a propulsion force for moving the boat 1 in the right-rearward direction forming an acute angle θ4 with respect to the left-right direction.

That is, the position P4 is a position where the outboard motors 12 and 13 generate a propulsion force for moving the boat 1 in the right-rearward direction (translational movement).

In the example shown in FIG. 3E, the lever of the joystick is tilted to the left. Thus, the tip of the lever of the joystick is positioned at the position P5 on the left side of the position P1. When the tip of the lever of the joystick is positioned at the position P5, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a propulsion force for moving the boat 1 to the left.

That is, the position P5 is a position where the outboard motors 12 and 13 generate a propulsion force for moving the boat 1 to the left (translational movement).

In the example shown in FIG. 3F, the lever of the joystick is tilted in a left-forward direction. Thus, the tip of the lever of the joystick is positioned at the position P6 on the left front side of the position P1. When the tip of the lever of the joystick is positioned at the position P6, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a propulsion force for moving the boat 1 in the left-forward direction forming an acute angle θ6 with respect to the left-right direction.

That is, the position P6 is a position where the outboard motors 12 and 13 generate a propulsion force for moving the boat 1 in the left-forward direction (translational movement).

In the example shown in FIG. 3G, the lever of the joystick is tilted in a left-rearward direction. Thus, the tip of the lever of the joystick is positioned at the position P7 on the left rear side of the position P1. When the tip of the lever of the joystick is positioned at the position P7, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a propulsion force for moving the boat 1 in the left-rearward direction forming an acute angle θ7 with respect to the left-right direction.

That is, the position P7 is a position where the outboard motors 12 and 13 generate a propulsion force for moving the boat 1 in the left-rearward direction (translational movement).

In the example shown in FIG. 3H, the lever of the joystick is tilted forward. Thus, the tip of the lever of the joystick is positioned at the position P8 on the front side of the position P1. When the tip of the lever of the joystick is positioned at the position P8, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a propulsion force for moving the boat 1 forward.

That is, the position P8 is a position where the outboard motors 12 and 13 generate a propulsion force for moving (advancing) the boat 1 forward.

In the example shown in FIG. 3I, the lever of the joystick is tilted rearward. Thus, the tip of the lever of the joystick is positioned at the position P9 on the rear side of the position P1. When the tip of the lever of the joystick is positioned at the position P9, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a propulsion force for moving the boat 1 rearward.

That is, the position P9 is a position where the outboard motors 12 and 13 generate a propulsion force for moving (reversing) the boat 1 rearward.

When the boat operator is not operating the operation unit 11D (the joystick), the tip of the lever of the joystick having an automatic return function is positioned at the position P1. The tip of the lever of the joystick can be positioned at positions such as positions P1 to P9 in accordance with an operation of the boat operator.

FIG. 4A-FIG. 4E and FIG. 5A and FIG. 5E are diagrams for describing an example of a movement path of the operation unit 11D (specifically, a movement path of the tip of the lever of the joystick) in the boat 1 of the first embodiment.

In the example shown in FIG. 4A, the operation unit 11D (specifically, the tip of the lever of the joystick) is moved from the position P1 to the position P2 and maintained at the position P2.

The movement path calculation unit 14A calculates a movement path P1→P2 of the tip of the lever of the joystick on the basis of the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P1 and the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P2.

The elapsed time calculation unit 14B calculates an elapsed time period from time t1 (see FIG. 6A-FIG. 6B) when the tip of the lever of the joystick is moved from the position P1 to the position P2. Specifically, the elapsed time calculation unit 14B calculates a time period while the tip of the lever of the joystick is continuously positioned at the position P2.

The propulsion force calculation unit 14C calculates a rightward propulsion force FR to be generated by the outboard motors 12 and 13 on the basis of the movement path P1→P2 of the tip of the lever of the joystick calculated by the movement path calculation unit 14A and the elapsed time period calculated by the elapsed time calculation unit 14B (the time period while the tip of the lever of the joystick is continuously positioned at the position P2). Specifically, the propulsion force calculation unit 14C calculates a magnitude of a propulsion force for moving the boat 1 to the right.

FIG. 6A and FIG. 6B are diagrams showing a relationship between the rightward propulsion force FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 and a timing (for example, time t1 when the tip of the lever of the joystick is moved from the position P1 to the position P2 or the like). The vertical axes in FIG. 6A and FIG. 6B represent the rightward propulsion force FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1. The horizontal axes in FIG. 6A and FIG. 6B represent time t1 when the tip of the lever of the joystick is moved from the position P1 to the position P2 or the like.

In the example shown in FIG. 6A, during a first period from time t1 when the tip of the lever of the joystick is moved from the position P1 to the position P2 to time t2, the propulsion force calculation unit 14C calculates a first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the first period from time t1 to time t2, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FR1.

Specifically, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FR1 less than a second propulsion force FR2 to be described below using the propulsion force calculation unit 14C so that the front portion 111 of the hull 11 starts to move rightward without the start of the movement of the front portion 111 of the hull 11 being later than the start of the movement of the rear portion 112 of the hull 11 during the first period from time t1 to time t2.

As a result, in the example shown in FIG. 6A, it is possible to restrict the front portion 111 of the hull 11 from starting to move later than the rear portion 112 of the hull 11 at time t1 and it is possible to restrict the boat 1 from turning to the left during the first period from time t1 to time t2.

In the example shown in FIG. 6A, subsequently, during a second period after time t2, the propulsion force calculation unit 14C calculates the second propulsion force FR2 greater than the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the second period after time t2, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the second propulsion force FR2 greater than the first propulsion force FR1.

As a result, in the example shown in FIG. 6A, the boat 1 can be quickly moved to the right according to a request of the boat operator during the second period after time t2.

In the example shown in FIG. 6B, during the first period from time t1 when the tip of the lever of the joystick is moved from the position P1 to the position P2 to time t2, the propulsion force calculation unit 14C calculates the first propulsion force FR1 (the first propulsion force FR1 is greater than or equal to a value FR1A and less than the second propulsion force FR2) as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the first period from time t1 to time t2, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FR1.

Specifically, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FR1 less than the second propulsion force FR2 using the propulsion force calculation unit 14C so that the front portion 111 of the hull 11 starts to move rightward without the start of the movement of the front portion 111 of the hull 11 being later than the start of the movement of the rear portion 112 of the hull 11 during the first period from time t1 to time t2.

As a result, in the example shown in FIG. 6B, it is possible to restrict the front portion 111 of the hull 11 from starting to move later than the rear portion 112 of the hull 11 at time t1 and it is possible to restrict the boat 1 from turning to the left during the first period from time t1 to time t2.

In the example shown in FIG. 6B, subsequently, during a second period after time t2, the propulsion force calculation unit 14C calculates the second propulsion force FR2 greater than the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the second period after time t2, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the second propulsion force FR2 greater than the first propulsion force FR1.

As a result, in the example shown in FIG. 6B, the boat 1 can be quickly moved to the right according to a request of the boat operator during the second period after time t2.

The boat operator may want to move the boat 1 in the right-forward direction (translational movement).

In such a case, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P3 as in the example shown in FIG. 4B.

The movement path calculation unit 14A calculates a movement path P1→P3 of the tip of the lever of the joystick on the basis of the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P1 and the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P3.

The elapsed time calculation unit 14B calculates an elapsed time period from a timing when the tip of the lever of the joystick is moved from the position P1 to the position P3. Specifically, the elapsed time calculation unit 14B calculates a time period while the tip of the lever of the joystick is continuously positioned at the position P3.

The propulsion force calculation unit 14C calculates a propulsion force to be generated by the outboard motors 12 and 13 on the basis of the movement path P1→P3 of the tip of the lever of the joystick calculated by the movement path calculation unit 14A and the elapsed time period calculated by the elapsed time calculation unit 14B (the time period while the tip of the lever of the joystick is continuously positioned at the position P3). Specifically, the propulsion force calculation unit 14C calculates a magnitude of a propulsion force for moving the boat 1 in the right-forward direction.

The outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-forward propulsion force of a magnitude calculated by the propulsion force calculation unit 14C.

As a result, the boat 1 moves in the right-forward direction (translational movement).

The boat operator may want to move the boat 1 to the right (translational movement) and the boat 1 may also be affected by a rearward force due to, for example, wind, tidal current, or the like.

In such a case, the operation unit 11D (the tip of the lever of the joystick) is first moved from the position P1 to the position P2, as in the example shown in FIG. 4C. Because the boat 1 may be swept rearward by a rearward force due to wind, tidal current, or the like, the operation unit 11D (the tip of the lever of the joystick) is subsequently moved from the position P2 to the position P3.

That is, in the example shown in FIG. 4C, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P3 via the position P2.

The movement path calculation unit 14A calculates a movement path P1→P2→P3 of the tip of the lever of the joystick on the basis of the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P1, the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P2, and the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P3.

The elapsed time calculation unit 14B calculates an elapsed time period from the timing when the tip of the lever of the joystick is moved from the position P1 to the position P2 and an elapsed time period from the timing when the tip of the lever of the joystick is moved from the position P2 to the position P3. Specifically, the elapsed time calculation unit 14B calculates a time period while the tip of the lever of the joystick is continuously positioned at the position P2 and a time period while the tip of the lever of the joystick is continuously positioned at the position P3.

The propulsion force calculation unit 14C calculates a propulsion force to be generated by the outboard motors 12 and 13 on the basis of the movement path P1→P2→P3 of the tip of the lever of the joystick calculated by the movement path calculation unit 14A and the elapsed time period calculated by the elapsed time calculation unit 14B (the time period for which the tip of the lever of the joystick is continuously positioned at the position P2 and the time period while the tip of the lever of the joystick is continuously positioned at the position P3). Specifically, the propulsion force calculation unit 14C calculates a magnitude of a propulsion force (i.e., a right-forward propulsion force) for moving the boat 1 to the right against the rearward force due to, for example, wind, tidal current, or the like.

The outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate the right-forward propulsion force of the magnitude calculated by the propulsion force calculation unit 14C.

From intensive research, the inventors of the present invention and the like have found that, if a magnitude of a forward-rearward direction component of the right-forward propulsion force generated by the outboard motors 12 and 13 when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P3 via the position P2 (the example shown in FIG. 4C) is set to be equal to a magnitude of a forward-rearward direction component of the right-forward propulsion force generated by the outboard motors 12 and 13 when the operation unit 11D (the tip of the lever of the joystick) is directly moved from the position P1 to the position P3 (the example shown in FIG. 4B), a magnitude of a forward-rearward direction component of the propulsion force against a rearward force, for example, due to wind, tidal current, or the like, may be not sufficient and the boat 1 may be swept rearward without being moved to the right (translational movement) according to a request of the boat operator.

Therefore, in the example shown in FIG. 4C, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-forward propulsion force having a forward-rearward direction component (specifically, a forward component) greater than that in the example of FIG. 4B during the period when the operation unit 11D is positioned at the position P3.

As a result, the boat 1 moves to the right (translational movement) according to a request of the boat operator and against the rearward force due to, for example, wind, tidal current, or the like.

FIG. 7A-FIG. 7D are diagrams showing a comparison of a propulsion force the outboard motor control device 14 causes the outboard motors 12 and 13 to generate in a right-forward direction in an example shown in FIG. 4B, a propulsion force the outboard motor control device 14 causes the outboard motors 12 and 13 to generate in the right-forward direction in an example shown in FIG. 4C, and the like.

FIG. 7A shows a right-forward propulsion force F11 the outboard motor control device 14 causes the outboard motors 12 and 13 to generate (i.e., calculated by the propulsion force calculation unit 14C) and a forward-rearward direction component F11F and a left-right direction component F11R of the right-forward propulsion force F11 when the operation unit 11D (the tip of the lever of the joystick) is moved directly from the position P1 to the position P3 (in the example shown in FIG. 4B

FIG. 7B shows a right-forward propulsion force F12 the outboard motor control device 14 causes the outboard motors 12 and 13 to generate (i.e., calculated by the propulsion force calculation unit 14C) and a forward-rearward direction component F12F and a left-right direction component F12R of the right-forward propulsion force F12 when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P3 via the position P2 (in the example shown in FIG. 4C).

In the examples shown in FIG. 7A and FIG. 7B, the magnitude of the left-right direction component F11R of the right-forward propulsion force F11 and the magnitude of the left-right direction component F12R of the right-forward propulsion force F12 are set to be equal. Further, the forward-rearward direction component F12F of the right-forward propulsion force F12 is set to be greater than the forward-rearward direction component F11F of the right-forward propulsion force F11. As a result, the right-forward propulsion force F12 is also greater than the right-forward propulsion force F11.

Accordingly, in the examples shown in FIG. 7A and FIG. 7B, even if the boat 1 is affected by a rearward force during a period in which the boat operator moves the operation unit 11D (the tip of the lever of the joystick) from the position P1 to the position P2 and moves the boat 1 to the right, the boat operator moves the operation unit 11D (the tip of the lever of the joystick) from the position P2 to the position P3, so that the outboard motors 12 and 13 generate the right-forward propulsion force F12 in which the forward-rearward direction component F12F is greater than the forward-rearward direction component F11F. As a result, the boat operator can move the boat 1 to the right without the boat 1 being swept rearward.

FIG. 8A-FIG. 8B are diagrams showing an example of a relationship between a rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 and a timing (for example, time t11 when the tip of the lever of the joystick is moved from the position P1 to the position P2 or the like) in the example shown in FIG. 4C and the like. Specifically, FIG. 8A is a diagram showing an example of a relationship between a rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 and a timing (for example, time t11 when the tip of the lever of the joystick is moved from the position P1 to the position P2 or the like) in the example shown in FIG. 4C. The vertical axis in FIG. 8A represents the rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1.

The horizontal axis in FIG. 8A represents time t11 when the tip of the lever of the joystick is moved from the position P1 to the position P2 and the like.

In the example shown in FIG. 8A, during the first period from time t11 when the tip of the lever of the joystick is moved from the position P1 to the position P2 to time t12, the propulsion force calculation unit 14C calculates the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the first period from time t11 to time t12, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FR1.

Next, during the second period from time t12 to time t13, the propulsion force calculation unit 14C calculates the second propulsion force FR2 greater than the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the second period from time t12 to time t13, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the second propulsion force FR2 greater than the first propulsion force FR1.

In the example shown in FIG. 8A, the tip of the lever of the joystick is moved from the position P2 to the position P3 at time t13 during the second period. After time t13, the propulsion force calculation unit 14C calculates the left-right direction component F12R shown in (B) of FIG. 7 as the left-right direction component FR of the right-forward propulsion force the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, after time t13, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate a right-forward propulsion force F12 (see FIG. 7B) including the left-right direction component F12R having the same magnitude as the second propulsion force FR2.

In the examples shown in FIG. 7A and FIG. 7B, as described above, a magnitude of the left-right direction component F11R of the right-forward propulsion force F11 and a magnitude of the left-right direction component F12R of the right-forward propulsion force F12 are set to be equal. Further, the forward-rearward direction component F12F of the right-forward propulsion force F12 is set to be greater than the forward-rearward direction component F11F of the right-forward propulsion force F11.

In another example, a magnitude of the forward-rearward direction component F12F of the right-forward propulsion force F12 and a magnitude of the forward-rearward direction component F11F of the right-forward propulsion force F11 are set to be equal and the left-right direction component F12R of the right-forward propulsion force F12 is set to be less than the left-right direction component F11R of the right-forward propulsion force F11. That is, in the present example, the right-forward propulsion force F12 is less than the right-forward propulsion force F11.

Accordingly, in the present example, even if the boat 1 is affected by a rearward force during the period in which the boat operator moves the operation unit 11D (the tip of the lever of the joystick) from the position P1 to the position P2 and moves the boat 1 to the right, the boat operator moves the operation unit 11D (the tip of the lever of the joystick) from the position P2 to the position P3, so that the outboard motors 12 and 13 generate the right-forward propulsion force F12 in which the left-right direction component F12R is less than the left-right direction component F11R. As a result, in the present example, the boat operator can also move the boat 1 to the right without the boat 1 being swept rearward.

FIG. 8B is a diagram showing an example of a relationship between a rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 and a timing (for example, time t11 when the tip of the lever of the joystick is moved from the position P1 to the position P2 or the like) in the other example described above and the like. The vertical axis in FIG. 8B shows the rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1. The horizontal axis in FIG. 8B shows time t11 when the tip of the lever of the joystick is moved from the position P1 to the position P2 and the like.

In the example shown in FIG. 8B, the propulsion force calculation unit 14C calculates the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate during the period from time t11 when the tip of the lever of the joystick is moved from the position P1 to the position P2 to time t12. That is, during the period from time t11 to time t12, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FR1.

Next, during the period from time t12 to time t13, the propulsion force calculation unit 14C calculates the second propulsion force FR2 greater than the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the period from time t12 to time t13, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the second propulsion force FR2 greater than the first propulsion force FR1.

In the example shown in FIG. 8B, the tip of the lever of the joystick is moved from the position P2 to the position P3 at time t13. During a period after time t13, the propulsion force calculation unit 14C calculates the left-right direction component F12R less than the left-right direction component F11R shown in FIG. 7A as the left-right direction component FR of the right-forward propulsion force the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during a period after time t13, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate a right-forward propulsion force F12 including the left-right direction component F12R less than the second propulsion force FR2.

Although the rightward propulsion force FR increases stepwise at time t12 in the examples shown in FIG. 8A and FIG. 8B, the rightward propulsion force FR may be increased linearly during the first period as in the example shown in FIG. 6B in another example.

When the boat is not affected by a force in the forward-rearward direction due to, for example, wind, tidal current, or the like, the boat operator may switch the direction of the boat 1 moving to the right (translational movement) from the right direction to the right-forward direction.

In such a case, the operation unit 11D (the tip of the lever of the joystick) is first moved from the position P1 to the position P2, as in the example shown in FIG. 4C. The operation unit 11D (the tip of the lever of the joystick) is subsequently moved from the position P2 to the position P3 so that the direction of the boat 1 moving to the right is switched from the right direction to the right-forward direction.

That is, in the example shown in FIG. 4C, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P3 via the position P2.

The movement path calculation unit 14A calculates a movement path P1→P2→P3 of the tip of the lever of the joystick on the basis of the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P1, the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P2, and the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P3.

The elapsed time calculation unit 14B calculates an elapsed time period from the timing when the tip of the lever of the joystick is moved from the position P1 to the position P2 and an elapsed time period from the timing when the tip of the lever of the joystick is moved from the position P2 to the position P3. Specifically, the elapsed time calculation unit 14B calculates a time period while the tip of the lever of the joystick is continuously positioned at the position P2 and a time period while the tip of the lever of the joystick is continuously positioned at the position P3.

The propulsion force calculation unit 14C calculates a propulsion force to be generated by the outboard motors 12 and 13 on the basis of the movement path P1→P2→P3 of the tip of the lever of the joystick calculated by the movement path calculation unit 14A and the elapsed time period calculated by the elapsed time calculation unit 14B (the time period while the tip of the lever of the joystick is continuously positioned at the position P2 and the time period while the tip of the lever of the joystick is continuously positioned at the position P3). Specifically, the propulsion force calculation unit 14C calculates a magnitude of a propulsion force (i.e., a right-forward propulsion force) for switching the direction of the boat 1 moving to the right from the right direction to the right-forward direction.

The outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-forward propulsion force of a magnitude calculated by the propulsion force calculation unit 14C.

From intensive research, the inventors of the present invention and the like have found that, because a rightward inertial force is generated in the boat 1 moving to the right, the boat operator may feel that a response operation of the boat 1 to a correction operation of the boat operator is slow (i.e., a changeover of the direction of the boat 1 from the right direction to the right-forward direction is slow) if a magnitude of a forward-rearward direction component of the right-forward propulsion force generated by the outboard motors 12 and 13 when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P3 via the position P2 (the example shown in FIG. 4C) is set to be equal to a magnitude of a forward-rearward direction component of the right-forward propulsion force generated by the outboard motors 12 and 13 when the operation unit 11D (the tip of the lever of the joystick) is directly moved from the position P1 to the position P3 (the example shown in FIG. 4B).

Therefore, in the example shown in FIG. 4C, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-forward propulsion force FR12 having a forward-rearward direction component greater than that in the example of FIG. 4B(specifically, in which the forward component F12F is greater than the forward component F11F) during the period when the operation unit 11D is positioned at the position P3. As a result, the direction of the boat 1 can be quickly switched from the right direction to the right-forward direction according to a request of the boat operator.

In another example, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-forward propulsion force FR12 having a left-right direction component less than that in the example of FIG. 4B (specifically, in which the forward component F12F is equal to the forward component F11F and the rightward component F12R is less than the rightward component F11R). As a result, in the present example, the direction of the boat 1 can also be quickly switched from the right direction to the right-forward direction according to a request of the boat operator.

Incidentally, if the control as shown in FIG. 8B is performed when a time period from time t12 to time t13 in FIG. 8B described above is short, the rightward propulsion force FR increases from the first propulsion force FR1 to the second propulsion force FR2 within a short time period (from t12 to t13) even though the boat operator does not intend to increase or decrease the rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR, and then the left-right direction component FR of the right-forward propulsion force decreases from the second propulsion force FR2 to the left-right direction component F12R.

Therefore, in the boat 1 of the first embodiment, when the time period (from t12 to t13) from time t12 to time t13 in FIG. 8A and FIG. 8B is short (when the time period from time t12 to time t13 is less than a threshold value TH1), the outboard motor control device 14 prohibits the control as shown in FIG. 8B from being performed and executes the control as shown in FIG. 8A.

That is, when the time period from time t12 to time t13 is less than the threshold value TH1, the outboard motor control device 14 prohibits the outboard motors 12 and 13 from generating the right-forward propulsion force F12 by decreasing the rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR from the second propulsion force FR2 to the left-right direction component F12R at time t13 as shown in FIG. 8B.

Thus, in the boat 1 of the first embodiment, it is possible to restrict the rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR from increasing or decreasing within the short time period (t12 to t13) even though the boat operator does not intend to increase or decrease the rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR.

Also, in the boat 1 of the first embodiment, when the time period (t12 to t13) from time t12 to time t13 in FIG. 8A and FIG. 8B is long (the time period from time t12 to time t13 is greater than or equal to the threshold value TH1), the outboard motor control device 14 allows the control as shown in FIG. 8B to be performed and executes either the control as shown in FIG. 8A or the control as shown in FIG. 8B.

That is, when the time period from time t12 to time t13 is greater than or equal to the threshold value TH1, the outboard motor control device 14 allows the outboard motors 12 and 13 to generate the right-forward propulsion force F12 by decreasing the rightward propulsion force (or the left-right direction component of the right-forward propulsion force) FR from the second propulsion force FR2 to the left-right direction component F12R at time t13 as shown in FIG. 8B.

Also, the boat operator may want to move the boat 1 in the right-rearward direction (translational movement).

In such a case, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P4 as in the example shown in FIG. 4D.

The movement path calculation unit 14A calculates a movement path P1→P4 of the tip of the lever of the joystick on the basis of the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P1 and the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P4.

The elapsed time calculation unit 14B calculates an elapsed time period from a timing when the tip of the lever of the joystick is moved from the position P1 to the position P4. Specifically, the elapsed time calculation unit 14B calculates a time period while the tip of the lever of the joystick is continuously positioned at the position P4.

The propulsion force calculation unit 14C calculates a propulsion force to be generated by the outboard motors 12 and 13 on the basis of the movement path P1→P4 of the tip of the lever of the joystick calculated by the movement path calculation unit 14A and the elapsed time period calculated by the elapsed time calculation unit 14B (the time period while the tip of the lever of the joystick is continuously positioned at the position P4). Specifically, the propulsion force calculation unit 14C calculates a magnitude of a propulsion force for moving the boat 1 in the right-rearward direction.

The outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-rearward propulsion force of the magnitude calculated by the propulsion force calculation unit 14C.

As a result, the boat 1 moves in the right-rearward direction (translational movement).

The boat operator may want to move the boat 1 to the right (translational movement) and the boat 1 may be affected by a forward force due to, for example, wind, tidal current, or the like.

In such a case, the operation unit 11D (the tip of the lever of the joystick) is first moved from the position P1 to the position P2, as in the example shown in FIG. 4E. Because the boat 1 may be swept forward by a forward force due to wind, tidal current, or the like, the operation unit 11D (the tip of the lever of the joystick) is subsequently moved from the position P2 to the position P4.

That is, in the example shown in FIG. 4E, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P4 via the position P2.

The movement path calculation unit 14A calculates a movement path P1→P2→P4 of the tip of the lever of the joystick on the basis of the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P1, the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P2, and the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P4.

The elapsed time calculation unit 14B calculates an elapsed time period from the timing when the tip of the lever of the joystick is moved from the position P1 to the position P2 and an elapsed time period from the timing when the tip of the lever of the joystick is moved from the position P2 to the position P4. Specifically, the elapsed time calculation unit 14B calculates a time period while the tip of the lever of the joystick is continuously positioned at the position P2 and a time period while the tip of the lever of the joystick is continuously positioned at the position P4.

The propulsion force calculation unit 14C calculates a propulsion force to be generated by the outboard motors 12 and 13 on the basis of the movement path P1→P2→P4 of the tip of the lever of the joystick calculated by the movement path calculation unit 14A and the elapsed time period calculated by the elapsed time calculation unit 14B (the time period while the tip of the lever of the joystick is continuously positioned at the position P2 and the time period while the tip of the lever of the joystick is continuously positioned at the position P4). Specifically, the propulsion force calculation unit 14C calculates a magnitude of a propulsion force (i.e., a right-rearward propulsion force) for moving the boat 1 to the right against the forward force due to, for example, wind, tidal current, or the like.

The outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-rearward propulsion force of the magnitude calculated by the propulsion force calculation unit 14C.

In the example shown in FIG. 4E, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-rearward propulsion force having a forward-rearward direction component (specifically, a rearward component) greater than that in the example of FIG. 4D during the period when the operation unit 11D is positioned at the position P4.

As a result, the boat 1 moves to the right (translational movement) according to a request of the boat operator and against the forward force due to, for example, wind, tidal current, or the like.

FIG. 7C shows a right-rearward propulsion force F21 the outboard motor control device 14 causes the outboard motors 12 and 13 to generate (i.e., calculated by the propulsion force calculation unit 14C) and a forward-rearward direction component F21B and a left-right direction component F21R of the right-rearward propulsion force F21 when the operation unit 11D (the tip of the lever of the joystick) is moved directly from the position P1 to the position P4 (in the example shown in FIG. 4D).

FIG. 7D shows a right-rearward propulsion force F22 the outboard motor control device 14 causes the outboard motors 12 and 13 to generate (i.e., calculated by the propulsion force calculation unit 14C) and a forward-rearward direction component F22B and a left-right direction component F22R of the right-rearward propulsion force F22 when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P4 via the position P2 (in the example shown in FIG. 4E).

In the examples shown in FIG. 7C and FIG. 7D, the magnitude of the left-right direction component F21R of the right-rearward propulsion force F21 and the magnitude of the left-right direction component F22R of the right-rearward propulsion force F22 are set to be equal. Further, the forward-rearward direction component F22B of the right-rearward propulsion force F22 is set to be greater than the forward-rearward direction component F21B of the right-rearward propulsion force F21. As a result, the right-rearward propulsion force F22 is also greater than the right-rearward propulsion force F21.

Accordingly, in the examples shown in FIG. 7C and FIG. 7D, even if the boat 1 is affected by a forward force during a period in which the boat operator moves the operation unit 11D (the tip of the lever of the joystick) from the position P1 to the position P2 and moves the boat 1 to the right, the boat operator moves the operation unit 11D (the tip of the lever of the joystick) from the position P2 to the position P4, so that the outboard motors 12 and 13 generate the right-rearward propulsion force F22 in which the forward-rearward direction component F22B is greater than the forward-rearward direction component F21B. As a result, the boat operator can move the boat 1 to the right without the boat 1 being swept forward.

FIG. 9A-FIG. 9B are diagrams showing an example of a relationship between a rightward propulsion force (or the left-right direction component of the right-rearward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 and a timing (for example, time t21 when the tip of the lever of the joystick is moved from the position P1 to the position P2 or the like) in the example shown in FIG. 4E and the like. Specifically, FIG. 9A is a diagram showing an example of a relationship between a rightward propulsion force (or the left-right direction component of the right-rearward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 and a timing (for example, time t21 when the tip of the lever of the joystick is moved from the position P1 to the position P2 or the like) in the example shown in FIG. 4E. The vertical axis in FIG. 9A represents the rightward propulsion force (or the left-right direction component of the right-rearward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1. The horizontal axis in FIG. 9A represents time t21 when the tip of the lever of the joystick is moved from the position P1 to the position P2 and the like.

In the example shown in FIG. 9A, during the first period from time t21 when the tip of the lever of the joystick is moved from the position P1 to the position P2 to time t22, the propulsion force calculation unit 14C calculates the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the first period from time t21 to time t22, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FR1.

Next, during the second period from time t22 to time t23, the propulsion force calculation unit 14C calculates the second propulsion force FR2 greater than the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the second period from time t22 to time t23, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the second propulsion force FR2 greater than the first propulsion force FR1.

In the example shown in FIG. 9A, the tip of the lever of the joystick is moved from the position P2 to the position P4 at time t23 during the second period. After time t23, the propulsion force calculation unit 14C calculates the left-right direction component F22R shown in FIG. 7D as the left-right direction component FR of the right-rearward propulsion force the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, after time t23, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate a right-rearward propulsion force F22 (see (D) of FIG. 7) including the left-right direction component F22R having the same magnitude as the second propulsion force FR2.

In the examples shown in FIG. 7C and FIG. 7D, as described above, a magnitude of the left-right direction component F21R of the right-rearward propulsion force F21 and a magnitude of the left-right direction component F22R of the right-rearward propulsion force F22 are set to be equal. Further, the forward-rearward direction component F22B of the right-rearward propulsion force F22 is set to be greater than the forward-rearward direction component F21B of the right-rearward propulsion force F21.

In another example, a magnitude of the forward-rearward direction component F22B of the right-rearward propulsion force F22 and a magnitude of the forward-rearward direction component F21B of the right-rearward propulsion force F21 are set to be equal, and the left-right direction component F22R of the right-rearward propulsion force F22 is set to be less than the left-right direction component F21R of the right-rearward propulsion force F21. That is, in the present example, the right-rearward propulsion force F22 is less than the right-rearward propulsion force F21.

Accordingly, in the present example, even if the boat 1 is affected by a forward force during the period in which the boat operator moves the operation unit 11D (the tip of the lever of the joystick) from the position P1 to the position P2, and moves the boat 1 to the right, the boat operator moves the operation unit 11D (the tip of the lever of the joystick) from the position P2 to the position P4, so that the outboard motors 12 and 13 generates the right-rearward propulsion force F22 in which the left-right direction component F22R is less than the left-right direction component F21R. As a result, in the present example, the boat operator can also move the boat 1 to the right without the boat 1 being swept forward.

FIG. 9B is a diagram showing an example of a relationship between a rightward propulsion force (or the left-right direction component of the right-rearward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 and a timing (for example, time t21 when the tip of the lever of the joystick is moved from the position P1 to the position P2 or the like) in the other example described above and the like. The vertical axis in FIG. 9B shows the rightward propulsion force (or the left-right direction component of the right-rearward propulsion force) FR generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1. The horizontal axis in FIG. 9B shows time t21 when the tip of the lever of the joystick is moved from the position P1 to the position P2 and the like.

In the example shown in FIG. 9B, the propulsion force calculation unit 14C calculates the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate during the period from time t21 when the tip of the lever of the joystick is moved from the position P1 to the position P2 to time t22. That is, during the period from time t21 to time t22, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FR1.

Next, during the period from time t22 to time t23, the propulsion force calculation unit 14C calculates the second propulsion force FR2 greater than the first propulsion force FR1 as the rightward propulsion force FR the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the period from time t22 to time t23, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the second propulsion force FR2 greater than the first propulsion force FR1.

In the example shown in FIG. 9B, the tip of the lever of the joystick is moved from the position P2 to the position P4 at time t23. During the period after time t23, the propulsion force calculation unit 14C calculates the left-right direction component F22R less than the left-right direction component F21R shown in FIG. 7C as the left-right direction component FR of the right-rearward propulsion force the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the period after time t23, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the right-rearward propulsion force F22 including the left-right direction component F22R less than the second propulsion force FR2.

Although the rightward propulsion force FR increases stepwise at time t22 in the examples shown in FIG. 9A and FIG. 9B, the rightward propulsion force FR may be increased linearly during the first period as in the example shown in FIG. 6B in another example.

When the boat is not affected by a force in the forward-rearward direction due to, for example, wind, tidal current, or the like, the boat operator may switch the direction of the boat 1 moving to the right (translational movement) from the right direction to the right-rearward direction.

In such a case, the operation unit 11D (the tip of the lever of the joystick) is first moved from the position P1 to the position P2, as in the example shown in FIG. 4E. The operation unit 11D (the tip of the lever of the joystick) is subsequently moved from the position P2 to the position P4 so that the direction of the boat 1 moving to the right is switched from the right direction to the right-rearward direction.

That is, in the example shown in FIG. 4E, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P4 via the position P2.

The movement path calculation unit 14A calculates a movement path P1→P2→P4 of the tip of the lever of the joystick on the basis of the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P1, the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P2, and the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P4.

The elapsed time calculation unit 14B calculates an elapsed time period from the timing when the tip of the lever of the joystick is moved from the position P1 to the position P2 and an elapsed time period from the timing when the tip of the lever of the joystick is moved from the position P2 to the position P4. Specifically, the elapsed time calculation unit 14B calculates a time period while the tip of the lever of the joystick is continuously positioned at the position P2 and a time period while the tip of the lever of the joystick is continuously positioned at the position P4.

The propulsion force calculation unit 14C calculates a propulsion force to be generated by the outboard motors 12 and 13 on the basis of the movement path P1→P2→P4 of the tip of the lever of the joystick calculated by the movement path calculation unit 14A and the elapsed time period calculated by the elapsed time calculation unit 14B (the time period while the tip of the lever of the joystick is continuously positioned at the position P2 and the time period while the tip of the lever of the joystick is continuously positioned at the position P4). Specifically, the propulsion force calculation unit 14C calculates a magnitude of a propulsion force (i.e., a right-rearward propulsion force) for switching the direction of the boat 1 moving to the right from the right direction to the right-rearward direction.

The outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-rearward propulsion force of the magnitude calculated by the propulsion force calculation unit 14C.

Therefore, in the example shown in FIG. 4E, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-rearward propulsion force FR22 having a forward-rearward direction component greater than that in the example of FIG. 4D (specifically, in which the rearward component F22B is greater than the rearward component F21B) during the period when the operation unit 11D is positioned at the position P4. As a result, the direction of the boat 1 can be quickly switched from the right direction to the right-rearward direction according to a request of the boat operator.

In another example, the outboard motor control device 14 causes the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate a right-rearward propulsion force FR22 having a left-right direction component less than that in the example of FIG. 4D (specifically, in which the rearward component F22B is equal to the rearward component F21B and the rightward component F22R is less than the rightward component F21R). As a result, in the present example, the direction of the boat 1 can also be quickly switched from the right direction to the right-rearward direction according to a request of the boat operator.

In the boat 1 of the first embodiment, when the time period (t22 to t23) from time t22 to time t23 in FIG. 9A and FIG. 9B is short (the time period from time t22 to time t23 is less than the threshold value TH1), the outboard motor control device 14 prohibits the control as shown in FIG. 9B from being performed and executes the control as shown in FIG. 9A.

That is, when the time period from time t22 to time t23 is less than the threshold value TH1, the outboard motor control device 14 prohibits the outboard motors 12 and 13 from generating the right-rearward propulsion force F22 by decreasing the rightward propulsion force (or the left-right direction component of the right-rearward propulsion force) FR from the second propulsion force FR2 to the left-right direction component F22R at time t23 as shown in FIG. 9B.

Thus, in the boat 1 of the first embodiment, it is possible to restrict the rightward propulsion force (or the left-right direction component of the right-rearward propulsion force) FR from increasing or decreasing within the short time period (t22 to t23) even though the boat operator does not intend to increase or decrease the rightward propulsion force (or the left-right direction component of the right-rearward propulsion force) FR.

Also, in the boat 1 of the first embodiment, when the time period (t22 to t23) from time t22 to time t23 in FIG. 9A and FIG. 9B is long (the time period from time t22 to time t23 is greater than or equal to the threshold value TH1), the outboard motor control device 14 allows the control as shown in FIG. 9B to be performed and executes either the control as shown in FIG. 9A or the control as shown in FIG. 9B.

That is, when the time period from time t22 to time t23 is greater than or equal to the threshold value TH1, the outboard motor control device 14 allows the outboard motors 12 and 13 to generate the right-rearward propulsion force F22 by decreasing the rightward propulsion force (or the left-right direction component of the right-rearward propulsion force) FR from the second propulsion force FR2 to the left-right direction component F22R at time t23 as shown in FIG. 9B.

The boat operator may want to move the boat 1 to the left (translational movement).

In such a case, the operation unit 11D (specifically, the tip of the lever of the joystick) is moved from the position P1 to the position P5 and maintained at the position P5 as in the example shown in FIG. 5A.

The movement path calculation unit 14A calculates a movement path P1→P5 of the tip of the lever of the joystick on the basis of the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P1 and the position of the lever at the timing when the tip of the lever of the joystick is positioned at the position P5.

The elapsed time calculation unit 14B calculates an elapsed time period from time t31 (see FIG. 10) when the tip of the lever of the joystick is moved from the position P1 to the position P5. Specifically, the elapsed time calculation unit 14B calculates a time period while the tip of the lever of the joystick is continuously positioned at the position P5.

The propulsion force calculation unit 14C calculates a leftward propulsion force FL to be generated by the outboard motors 12 and 13 on the basis of the movement path P1→P5 of the tip of the lever of the joystick calculated by the movement path calculation unit 14A and the elapsed time period calculated by the elapsed time calculation unit 14B (the time period while the tip of the lever of the joystick is continuously positioned at the position P5). Specifically, the propulsion force calculation unit 14C calculates a magnitude of a propulsion force for moving the boat 1 to the left.

FIG. 10 is a diagram showing a relationship between a leftward propulsion force FL generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 and a timing (for example, time t31 when the tip of the lever of the joystick is moved from the position P1 to the position P5 or the like). The vertical axes in FIG. 10A and FIG. 10B represent the leftward propulsion force FL generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1. The horizontal axes in FIG. 10A and FIG. 10B represent time t31 when the tip of the lever of the joystick is moved from the position P1 to the position P5 or the like.

In the example shown in FIG. 10A, during the first period from time t31 when the tip of the lever of the joystick is moved from the position P1 to the position P5 to time t32, the propulsion force calculation unit 14C calculates a first propulsion force FL1 as the leftward propulsion force FL the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the first period from time t31 to time t32, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FL1.

Specifically, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FL1 less than a second propulsion force FL2 to be described below using the propulsion force calculation unit 14C so that the front portion 111 of the hull 11 starts to move leftward without the start of the movement of the front portion 111 of the hull 11 being later than the start of the movement of the rear portion 112 of the hull 11 during the first period from time t31 to time t32.

As a result, in the example shown in FIG. 10A, it is possible to restrict the front portion 111 of the hull 11 from starting to move later than the rear portion 112 of the hull 11 at time t31 and it is possible to restrict the boat 1 from turning to the right during the first period from time t31 to time t32.

In the example shown in FIG. 10A, subsequently, during a second period after time t32, the propulsion force calculation unit 14C calculates the second propulsion force FL2 greater than the first propulsion force FL1 as the leftward propulsion force FL the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the second period after time t32, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the second propulsion force FL2 greater than the first propulsion force FL1.

As a result, in the example shown in FIG. 10A, the boat 1 can be quickly moved to the left according to a request of the boat operator during the second period after the time t32.

In the example shown in FIG. 10B, during the first period from time t31 when the tip of the lever of the joystick is moved from the position P1 to the position P5 to time t32, the propulsion force calculation unit 14C calculates the first propulsion force FL1 (the first propulsion force FL1 is greater than or equal to a value FL1A and less than the second propulsion force FL2) as a leftward propulsion force FL the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the first period from time t31 to time t32, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FL1.

Specifically, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the first propulsion force FL1 less than the second propulsion force FL2 using the propulsion force calculation unit 14C so that the front portion 111 of the hull 11 starts to move leftward without the start of the movement of the front portion 111 of the hull 11 being later than the start of the movement of the rear portion 112 of the hull 11 during the first period from time t31 to time t32.

As a result, in the example shown in FIG. 10B, it is possible to restrict the front portion 111 of the hull 11 from starting to move later than the rear portion 112 of the hull 11 at time t31 and it is possible to restrict the boat 1 from turning to the right during the first time period from time t31 to time t32.

In the example shown in FIG. 10B, subsequently, during a second period after time t32, the propulsion force calculation unit 14C calculates the second propulsion force FL2 greater than the first propulsion force FL1 as the leftward propulsion force FL the outboard motor control device 14 causes the outboard motors 12 and 13 to generate. That is, during the second period from time t32, the outboard motor control device 14 causes the outboard motors 12 and 13 to generate the second propulsion force FL2 greater than the first propulsion force FL1.

As a result, in the example shown in FIG. 10B, the boat 1 can be quickly moved to the left according to a request of the boat operator during the second period after time t32.

The boat operator may want to move the boat 1 in the left-forward direction (translational movement).

In such a case, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P6 as in the example shown in FIG. 5B

The outboard motor control device 14 executes control in which control executed when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P3 is reversed left and right.

As a result, the boat 1 moves in the left-forward direction (translational movement).

The boat operator may want to move the boat 1 to the left (translational movement) and the boat 1 may also be affected by a rearward force due to, for example, wind, tidal current, or the like.

In such a case, the operation unit 11D (the tip of the lever of the joystick) is first moved from the position P1 to the position P5, as in the example shown in FIG. 5C. Because the boat 1 may be swept rearward by a rearward force due to wind, tidal current, or the like, the operation unit 11D (the tip of the lever of the joystick) is subsequently moved from the position P5 to the position P6.

That is, in the example shown in FIG. 5C, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P6 via the position P5.

The outboard motor control device 14 executes control in which the control executed when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P3 via the position P2 is reversed left and right.

As a result, the boat 1 moves to the left (translational movement) according to a request of the boat operator and against the rearward force due to, for example, wind, tidal current, or the like.

When the boat is not affected by a force in the forward-rearward direction due to, for example, wind, tidal current, or the like, the boat operator may switch the direction of the boat 1 moving to the left (translational movement) from the left direction to the left-forward direction.

In such a case, the operation unit 11D (the tip of the lever of the joystick) is first moved from the position P1 to the position P5, as shown in the example shown in FIG. 5C. The operation unit 11D (the tip of the lever of the joystick) is subsequently moved from the position P5 to the position P6 so that the direction of the boat 1 moving to the left is switched from the left direction to the left-forward direction.

That is, in the example shown in FIG. 5C, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P6 via the position P5.

The outboard motor control device 14 executes control in which the control executed when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P3 via the position P2 is reversed left and right.

As a result, the direction of the boat 1 can be quickly switched from the left direction to the left-forward direction according to a request of the boat operator.

Also, the boat operator may want to move the boat 1 in the left-rearward direction (translational movement).

In such a case, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P7 as in the example shown in FIG. 5D.

The outboard motor control device 14 executes control in which the control executed when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P4 is reversed left and right.

As a result, the boat 1 moves in the left-rearward direction (translational movement).

The boat operator may want to move the boat 1 to the left (translational movement) and the boat 1 may also be affected by a forward force due to, for example, wind, tidal current, or the like.

In such a case, the operation unit 11D (the tip of the lever of the joystick) is first moved from the position P1 to the position P5, as in the example shown in FIG. 5E. Because the boat 1 may be swept forward by a forward force due to wind, tidal current, or the like, the operation unit 11D (the tip of the lever of the joystick) is subsequently moved from the position P5 to the position P7.

That is, in the example shown in FIG. 5E, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P7 via the position P5.

The outboard motor control device 14 executes control in which the control executed when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P4 via the position P2 is reversed left and right.

As a result, the boat 1 moves to the left (translational movement) according to a request of the boat operator and against the forward force due to, for example, wind, tidal current, or the like.

When the boat is not affected by a force in the forward-rearward direction due to, for example, wind, tidal current, or the like, the boat operator may switch the direction of the boat 1 moving to the left (translational movement) from the left direction to the left-rearward direction.

In such a case, the operation unit 11D (the tip of the lever of the joystick) is first moved from the position P1 to the position P5, as in the example shown in FIG. 5E. The operation unit 11D (the tip of the lever of the joystick) is subsequently moved from the position P5 to the position P7 so that the direction of the boat 1 moving to the left is switched from the left direction to the left-rearward direction.

That is, in the example shown in FIG. 5E, the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P7 via the position P5.

The outboard motor control device 14 executes control in which the control executed when the operation unit 11D (the tip of the lever of the joystick) is moved from the position P1 to the position P4 via the position P2 is reversed left and right.

As a result, the direction of the boat 1 can be quickly switched from the left direction to the left-rearward direction according to a request of the boat operator.

FIG. 11 is a flowchart for describing an example of a process executed by the outboard motor control device 14 of the first embodiment.

The process shown in FIG. 11 starts when the operation unit 11D (the joystick) has received an input operation for operating the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 of the outboard motors 12 and 13.

In the example shown in FIG. 11, in step S10, the outboard motor control device 14 acquires a position of the operation unit 11D (a position of the lever of the joystick) detected by a sensor such as a micro switch.

Subsequently, in step S20, the movement path calculation unit 14A of the outboard motor control device 14 calculates a movement path of the operation unit 11D (a movement path of the tip of the lever of the joystick) on the basis of a plurality of positions of the operation unit 11D (a plurality of positions of the lever of the joystick) acquired in step S10.

Next, in step S30, the elapsed time calculation unit 14B of the outboard motor control device 14 calculates an elapsed time period from a timing when the operation unit 11D (the tip of the lever of the joystick) is moved to each position.

Next, in step S40, the propulsion force calculation unit 14C of the outboard motor control device 14 calculates a propulsion force to be generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 on the basis of the movement path of the operation unit 11D (the movement path of the tip of the lever of the joystick) calculated in step S20 and the elapsed time period calculated in step S30.

Next, in step S50, the outboard motor control device 14 controls the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 of the outboard motors 12 and 13 so that the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 of the outboard motors 12 and 13 generate the propulsion force calculated in step S20.

Second Embodiment

Hereinafter, a second embodiment of an outboard motor control device, an outboard motor control method, and a program of the present invention will be described.

A boat 1 to which an outboard motor control device 14 of the second embodiment is applied has a configuration similar to that of the boat 1 to which the outboard motor control device 14 of the first embodiment described above is applied, except for differences to be described below. Accordingly, the boat 1 of the second embodiment can obtain effects similar to those of the boat 1 of the first embodiment described above, except for differences to be described below.

FIG. 12 is a diagram showing an example of the boat 1 to which the outboard motor control device 14 of the second embodiment is applied.

As described above, in the boat 1 of the first embodiment (the examples shown in FIG. 1 and FIG. 2), the operation unit 11D includes the joystick having the lever.

On the other hand, in the boat 1 of the second embodiment (the example shown in FIG. 12), an operation unit 11D includes a touch panel. A boat operator can operate steering actuators 12A2 and 13A2 and propulsion units 12A1 and 13A1 by operating a steering device 11A (a steering wheel) and remote control devices 11B and 11C (remote control levers) and can also operate the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 by operating the operation unit 11D (a touch panel).

In another example, a hull 11 may not include the steering device 11A, the remote control device 11B, and the remote control device 11C.

In the example shown in FIG. 12, the outboard motor control device 14 controls the steering actuator 12A2 and the propulsion unit 12A1 of an outboard motor 12 and the steering actuator 13A2 and the propulsion unit 13A1 of an outboard motor 13 on the basis of an input operation on the operation unit 11D.

Specifically, the outboard motor control device 14 controls a magnitude and a direction of a propulsion force of the boat 1 that is generated by the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 on the basis of, for example, a flick input operation on the operation unit 11D (the touch panel).

In the flick input operation, for example, a boat operator slides a finger pressing the touch panel in a desired direction while pressing the touch panel.

A movement path calculation unit 14A calculates a movement path of the operation unit 11D. Specifically, the movement path calculation unit 14A calculates the movement path of the finger the boat operator slides while pressing the touch panel.

An elapsed time calculation unit 14B calculates an elapsed time period from a timing when the operation unit 11D (the finger of the boat operator who presses the touch panel) is moved to a certain position.

A propulsion force calculation unit 14C calculates a propulsion force to be generated by the outboard motors 12 and 13 on the basis of the movement path of the operation unit 11D calculated by the movement path calculation unit 14A (the movement path of the finger allowed to slid while pressing the touch panel) and the elapsed time period calculated by the elapsed time calculation unit 14B.

In the example shown in FIG. 12, the operation unit 11D is configured so that a flick input operation can be performed on the operation unit 11D (the touch panel) and a rotation input operation can be performed.

For example, in a state in which one finger is in contact with the touch panel and fixed as a center point, the boat operator performs a rotation input operation by sliding another finger in a circumferential direction while pressing the touch panel.

When the boat operator performs a clockwise rotation input operation on the operation unit 11D (the touch panel), the outboard motor control device 14 controls the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 so that the hull 11 turns to the right. On the other hand, when the boat operator performs a counterclockwise rotation input operation on the operation unit 11D (the touch panel), the outboard motor control device 14 controls the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 so that the hull 11 turns to the left.

Also, when the boat operator performs a flick input operation on the operation unit 11D (the touch panel), the outboard motor control device 14 controls the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 so that the hull 11 moves in a direction in which the boat operator's finger is allowed to slide while the hull 11 maintains its attitude. That is, when the boat operator performs a flick input operation on the operation unit 11D (the touch panel), a front portion 111 of the hull 11 and a rear portion 112 of the hull 11 are translated.

When the boat operator does not perform a flick input operation on the operation unit 11D (the touch panel) (i.e., when the boat operator's finger does not touch the touch panel), the operation unit 11D is in a state similar to the state shown in FIG. 3A. As a result, the outboard motor control device 14 does not cause the steering actuators 12A2 and 13A2 and the propulsion units 12A1 and 13A1 to generate the propulsion force of the boat 1.

Although modes for carrying out the present invention have been described above using the embodiments, the present invention is not limited to the embodiments and various modifications and replacements can be applied without departing from the spirit and scope of the present invention. The configurations described in the above-described embodiments and the above-described examples may be combined.

Also, all or some of the functions of the parts provided in the outboard motor control device 14 according to the above-described embodiment may be implemented by recording a program for implementing the functions on a computer-readable recording medium and causing a computer system to read and execute the program recorded on the recording medium. Also, the “computer system” described here is assumed to include an operating system (OS) and hardware such as peripheral devices.

Also, the “computer-readable recording medium” refers to a flexible disk, a magneto-optical disc, a ROM, a portable medium such as a CD-ROM, or a storage unit such as a hard disk embedded in the computer system. Further, the “computer-readable recording medium” may include a computer-readable recording medium for dynamically retaining the program for a short time period as in a communication line when the program is transmitted via a network such as the Internet or a communication circuit such as a telephone circuit and a computer-readable recording medium for retaining the program for a given time period as in a volatile memory inside the computer system including a server and a client when the program is transmitted. Also, the above-described program may be a program for implementing some of the above-described functions. Further, the above-described program may be a program capable of implementing the above-described function in combination with a program already recorded on the computer system.

REFERENCE SIGNS LIST

1 Boat

111 Front portion

112 Rear portion

11 Hull

11A Steering device

11B Remote control device

11C Remote control device

11D Operation unit

P1 Position

P2 Position

P3 Position

P4 Position

P5 Position

P6 Position

P7 Position

P8 Position

P9 Position

12 Outboard motor

12A Outboard motor main body

12A1 Propulsion unit

12A2 Steering actuator

12AX Steering shaft

12B Bracket

13 Outboard motor

13A Outboard motor main body

13A1 Propulsion unit

13A2 Steering actuator

13AX Steering shaft

13B Bracket

14 Outboard motor control device

14A Movement path calculation unit

14B Elapsed time calculation unit

14C Propulsion force calculation unit 

What is claimed is:
 1. An outboard motor control device for controlling a plurality of outboard motors disposed on a rear portion of a hull of a boat, wherein each of the plurality of outboard motors comprises a propulsion unit configured to generate a propulsion force and a steering actuator, wherein the boat comprises an operation unit configured to operate the steering actuator and the propulsion unit, wherein the operation unit is able to be positioned at least at a first position that is a position where the plurality of outboard motors do not generate a propulsion force of the boat and a second position that is a position where the plurality of outboard motors generate a propulsion force for moving the boat in a left-right direction, and wherein, when the operation unit is moved from the first position to the second position and maintained at the second position, the outboard motor control device causes the plurality of outboard motors to generate a first propulsion force during a first period from a first timing when the operation unit is moved to the second position to a second timing and subsequently causes the plurality of outboard motors to generate a second propulsion force greater than the first propulsion force during a second period after the second timing.
 2. The outboard motor control device according to claim 1, wherein the outboard motor control device causes the plurality of outboard motors to generate the first propulsion force less than the second propulsion force during the first period so that a front portion of the hull starts to move in the left-right direction without the start of the movement of the front portion of the hull being later than a start of a movement of the rear portion of the hull.
 3. The outboard motor control device according to claim 2, wherein the second position comprises a right position that is a position on a right side of the first position and is a position where the plurality of outboard motors generate a propulsion force for moving the boat rightward, and wherein, when the operation unit is moved from the first position to the right position at the first timing and maintained at the right position during the second period, the outboard motor control device causes the plurality of outboard motors to generate a rightward first propulsion force less than the second propulsion force during the first period so that the front portion of the hull starts to move rightward without the start of the movement of the front portion of the hull being later than the start of the movement of the rear portion of the hull and subsequently causes the plurality of outboard motors to generate a rightward second propulsion force during the second period.
 4. The outboard motor control device according to claim 3, wherein the operation unit is able to be further positioned at a right oblique position that is a position on a right front side or a right rear side of the first position and is a position where the plurality of outboard motors generate a propulsion force for moving the boat in a right-forward direction or a right-rearward direction, and wherein a forward-rearward direction component of a right-forward or right-rearward propulsion force generated by the plurality of outboard motors when the operation unit is moved from the right position to the right oblique position at a third timing during the second period is greater than a forward-rearward direction component of a right-forward or right-rearward propulsion force generated by the plurality of outboard motors when the operation unit is directly moved from the first position to the right oblique position, or wherein a left-right direction component of the right-forward or right-rearward propulsion force generated by the plurality of outboard motors when the operation unit is moved from the right position to the right oblique position at the third timing is less than a left-right direction component of the right-forward or right-rearward propulsion force generated by the plurality of outboard motors when the operation unit is directly moved from the first position to the right oblique position.
 5. The outboard motor control device according to claim 4, wherein, when a time period from the second timing to the third timing is less than a threshold value, the outboard motor control device prohibits the plurality of outboard motors from generating the right-forward or right-rearward propulsion force by reducing the second propulsion force at the third timing, and wherein, when the time period from the second timing to the third timing is greater than or equal to the threshold value, the outboard motor control device allows the plurality of outboard motors to generate the right-forward or right-rearward propulsion force by reducing the second propulsion force at the third timing.
 6. The outboard motor control device according to claim 2, wherein the second position comprises a left position that is a position on a left side of the first position and is a position where the plurality of outboard motors generate a propulsion force for moving the boat leftward, and wherein, when the operation unit is moved from the first position to the left position at the first timing and maintained at the left position during the second period, the outboard motor control device causes the plurality of outboard motors to generate a leftward first propulsion force less than the second propulsion force during the first period so that the front portion of the hull starts to move leftward without the start of the movement of the front portion of the hull being later than the start of the movement of the rear portion of the hull and subsequently causes the plurality of outboard motors to generate a leftward second propulsion force during the second period.
 7. The outboard motor control device according to claim 6, wherein the operation unit is able to be further positioned at a left oblique position that is a position on a left front side or a left rear side of the first position and is a position where the plurality of outboard motors generate a propulsion force for moving the boat in a left-forward direction or a left-rearward direction, and wherein a forward-rearward direction component of a left-forward or left-rearward propulsion force generated by the plurality of outboard motors when the operation unit is moved from the left position to the left oblique position at a third timing during the second period is greater than a forward-rearward direction component of a left-forward or left-rearward propulsion force generated by the plurality of outboard motors when the operation unit is directly moved from the first position to the left oblique position, or wherein a left-right direction component of the left-forward or left-rearward propulsion force generated by the plurality of outboard motors when the operation unit is moved from the left position to the left oblique position at the third timing is less than a left-right direction component of the left-forward or left-rearward propulsion force generated by the plurality of outboard motors when the operation unit is directly moved from the first position to the left oblique position.
 8. The outboard motor control device according to claim 7, wherein, when a time period from the second timing to the third timing is less than a threshold value, the outboard motor control device prohibits the plurality of outboard motors from generating the left-forward or left-rearward propulsion force by reducing the second propulsion force at the third timing, and wherein, when the time period from the second timing to the third timing is greater than or equal to the threshold value, the outboard motor control device allows the plurality of outboard motors to generate the left-forward or left-rearward propulsion force by reducing the second propulsion force at the third timing.
 9. An outboard motor control method of controlling a plurality of outboard motors disposed on a rear portion of a hull of a boat, wherein each of the plurality of outboard motors comprises a propulsion unit configured to generate a propulsion force and a steering actuator, wherein the boat comprises an operation unit configured to operate the steering actuator and the propulsion unit and an outboard motor control device configured to control the plurality of outboard motors, wherein the operation unit is able to be positioned at least at a first position that is a position where the plurality of outboard motors do not generate a propulsion force of the boat and a second position that is a position where the plurality of outboard motors generate a propulsion force for moving the boat in a left-right direction, and wherein the outboard motor control method comprises: a first step in which the outboard motor control device causes the plurality of outboard motors to generate a first propulsion force during a first period from a first timing when the operation unit is moved to the second position to a second timing when the operation unit is moved from the first position to the second position and maintained at the second position; and a second step in which the outboard motor control device causes the plurality of outboard motors to generate a second propulsion force greater than the first propulsion force during a second period after the second timing when the operation unit is moved from the first position to the second position and maintained at the second position.
 10. A program for controlling a plurality of outboard motors disposed on a rear portion of a hull of a boat, wherein each of the plurality of outboard motors comprises a propulsion unit configured to generate a propulsion force and a steering actuator, wherein the boat comprises an operation unit configured to operate the steering actuator and the propulsion unit, wherein the operation unit is able to be positioned at least at a first position that is a position where the plurality of outboard motors do not generate a propulsion force of the boat and a second position that is a position where the plurality of outboard motors generate a propulsion force for moving the boat in a left-right direction, and wherein the program causes a computer mounted in the boat to execute: a first step in which the plurality of outboard motors generate a first propulsion force during a first period from a first timing when the operation unit is moved to the second position to a second timing when the operation unit is moved from the first position to the second position and maintained at the second position; and a second step in which the plurality of outboard motors generate a second propulsion force greater than the first propulsion force during a second period after the second timing when the operation unit is moved from the first position to the second position and maintained at the second position. 